A review of high-performance MEMS sensors for resource exploration and geophysical applications

MEMS sensors have the advantages of small volume,lightweight,and low cost,therefore,have been widely used in the fields of consumer electronics,industry,health,defence,and aerospace.With their ever-improving performance,MEMS sensors have also started to be used in resource exploration and geophysical applications.However,the requirements of high-precision MEMS sensors for geophysical applications have not been specified in detail.Therefore,this paper systematically analyzes the requirements of high-performance MEMS sensors for prospecting and geophysical applications,including seismic surveillance,Earth tide,volcanic activity monitoring for natural disasters;seismic,gravity,and magnetic resource prospecting;drilling process monitoring and local gravity measurement for gravity aided navigation.Focusing on the above applications,this paper summarizes the state-of-the-art of research on high-performance MEMS sensors for resource exploration and geophysical applications.Several off-the-shelf MEMS sensors have been used for earthquake monitoring,seismic exploration and drilling process monitoring,and a range of MEMS research prototype sensors have successfully been employed for Earth tides measurement and are promising to be used for gravity exploration.MEMS magnetometers should have a lower noise floor to meet the demand for magnetic exploration.MEMS gravity gradiometers are still under early development and will not be deployable in short-term.Highperformance MEMS sensors hold the advantages of low-cost,high integration,and capability of working in extreme environments;therefore,they are likely to gradually replace some conventional geophysical instruments in some application areas.

Microporous metal-organic framework materials for efficient capture and separation of greenhouse gases

The release of anthropogenic greenhouse gases into the atmosphere poses serious risks to the environment and human health,and is a global threat of growing concern.In order to ameliorate the greenhouse gas emission problems,the efficient capture and separation of these greenhouse gases are greatly meaningful.Metal-organic framework(MOF)materials,a relatively new kind of organic-inorganic hybrid porous materials with unique framework features,tunable pore environment and high surface areas,have been widely studied as regards their applicability to this implementation.And the well-defined structures of MOF materials greatly promote the understanding of structure-property relationships.In this review,we intend to provide a profound account of significant progress in the field of capture and separation of greenhouse gases using MOFs as adsorbents,including carbon dioxide,methane,nitrous oxide and fluorocompounds(such as perfluorocarbons,sulfur hexafluoride,hydrochlorocarbons,and hydrofluocarbons).The strategies used to realize the efficient capture and separation of greenhouse gases have been summarized,and the relationships between the frameworks,their capture and separation performances and mechanisms are discussed.Furthermore,the existing challenges and perspectives with regard to the development of MOF materials for the capture and separation of greenhouse gases and industrial practical application are outlined to further promote this very significant and active emerging topic.

Robust microporous metal-organic framework with high moisture tolerance for efficient separation of propylene from propane

Adsorptive separation of propylene(C_(3)H_(6))from propylene/propane(C_(3)H_(8))is desired to replace energy-intensive cryogenic distillation for its energy efficiency,economical viability,and environment friendship.In this work,we report a cupper-based robust microporous metal-organic framework,Cu-Hmpba,constructed by the hard soft acid-base principle using the bifunctional pyridylcarboxylate ligand featuring methyl group,for high-efficient separation of the propylene/propane mixture.Under the synergistic effect of the protective group and hard soft acid base principle,Cu-Hmpba possesses good solvents stability,especially water stability.Cu-Hmpba exhibits the adsorption capacity of C_(3)H_(6)with 2.10 mmol g^(-1)and good equimolar C_(3)H_(6)/C_(3)H_(8)selectivity with 2.24 at ambient conditions.The gas adsorption experiments,IAST selectivity calculations and theoretical calculations comprehensively support the selective adsorption toward C_(3)H_(6)among C_(3)H_(6)/C_(3)H_(8)mixture.Furthermore,it could maintain stable under moisture environment,suggesting its potential for the industrial separation of C_(3)H_(6)/C_(3)H_(8)mixture.The results of experiments and simulations demonstrate that the Cu-Hmpba would be a candidate adsorbent for the separation and purification of light hydrocarbons,and this work provides the insight of syn-thesizing stable MOF materials for separating high-value chemicals.